With continuous development of communication technologies, users put forward higher requirements for data bandwidth and signal quality of a mobile communication network. In an era developing from 2G network to 3G network and LTE network, mobile communication operators should study on convergence and multiplexing of different communication networks to offer the users reliable and high quality services.
In order to flexibly achieve the convergence and multiplexing of different communication networks in a user terminal, a common solution is to integrate in the user terminal several signal processing modules respectively supporting different communication network standards; hence, the user terminal may be connected to a communication network based on an actual situation. As shown in FIG. 1, two signal processing modules are integrated in a Modem supporting multiple standards in the user terminal, one is a signal processing module supporting a communication network standard of Global System for Mobile Communications (GSM), while the other is a signal processing module supporting a communication network standard of Time Division-Synchronous Code Division Multiple Access (TD-SCDMA). In addition, the Modem shown in FIG. 1 further includes a Central Processing Unit (CPU) and a Digital Signal Processor (DSP).
With the user terminal shown in FIG. 1, when it is required to run a Real Time Operating System (RTOS) supporting any communication network standard in the user terminal so as to establish connection between the user terminal and the communication network, since the user terminal merely includes one set of hardware resources (the CPU and the DSP shown in FIG. 1 and other hardware resources such as a memory, etc., which are not shown in FIG. 1) for running one RTOS, only one RTOS may be run in the user terminal and accordingly the user terminal may merely be connected to one communication network.